1. Field of the Invention
The present invention relates to a window opening and closing controller for controlling opening and closing of a window of a vehicle, etc.
2. Description of Related Art
The window opening and closing controller (hereinafter called a “power window device”) used in an automobile is a device for raising and lowering a window glass of a door and opening and closing the window by rotating a motor in the normal and reverse directions by the operation of a switch. FIG. 1 is a block diagram showing the electric construction of the power window device. Reference numerals 1, 2 and 4 respectively designate an operation switch for performing the opening and closing operations of the window, a motor driving circuit for driving a motor 3, and a rotary encoder for outputting a pulse synchronized with the rotation of the motor 3. Reference numerals 5, 6 and 7 respectively designate a pulse detecting circuit for detecting the pulse outputted from the rotary encoder 4, a memory constructed from a ROM, a RAM, etc., and a door closing detecting switch for detecting the closing of the door. Reference numerals 8 and 9 respectively designate an acceleration sensor for detecting acceleration due to a vibration and an impact applied to a vehicle body, and a control section constructed by a CPU for controlling the opening and closing operations of the window.
When the operation switch 1 is operated, a window opening and closing command is given to the control section 9, and the motor 3 is rotated by the motor driving circuit 2 in the normal or reverse direction. A window opening and closing mechanism is operated in association with the motor 3 by rotating the motor 3 so that the window is opened and closed. The pulse detecting circuit 5 detects the pulse outputted from the rotary encoder 4. The control section 9 calculates the opening and closing amount of the window and a motor speed on the basis of this detecting result, and controls the rotation of the motor 3 through the motor driving circuit 2.
FIG. 2 is a schematic construction view showing one example of the operation switch 1. The operation switch 1 is constructed from an operation knob 11 able to be rotated in the ab direction with a shaft Q as a center, a rod 12 arranged integrally with this operation knob 11, and a publicly known slide switch 13. Reference numerals 14 and 20 respectively designate an actuator of the slide switch 13, and a cover of a switch unit into which the operation switch 1 is assembled. The lower end of the rod 12 is engaged with the actuator 14 of the slide switch 13. When the operation knob 11 is rotated in the ab direction, the actuator 14 is moved in the cd direction through the rod 12, and an unillustrated contact of the slide switch 13 is switched in accordance with its moving position.
The operation knob 11 can be switched to the respective positions of auto closing AC, manual closing MC, neutral N, manual opening MO and auto opening AO. FIG. 2 shows a state in which the operation knob 11 is located in the position of neutral N. When the operation knob 11 is rotated by a constant amount from this position to the a-direction and is set to the position of manual closing MC, a manual closing operation for closing the window by a manual operation is performed. When the operation knob 11 is further rotated in the a-direction from this position and is set to the position of auto closing AC, an auto closing operation for closing the window by an auto operation is performed. Further, when the operation knob 11 is rotated by a constant amount from the position of neutral N in the b-direction and is set to the position of manual opening MO, a manual opening operation for opening the window by a manual operation is performed. When the operation knob 11 is further rotated from this position in the b-direction and is set to the position of auto opening AO, an auto opening operation for opening the window by an auto operation is performed. An unillustrated spring is arranged in the operation knob 11. When a hand is separated from the rotated operation knob 11, the operation knob 11 is returned to the position of neutral N by the force of the spring.
In the case of the manual operation, the operation for closing or opening the window is performed only while the operation knob 11 is manually held continuously in the position of manual closing MC or manual opening MO. When the hand is separated from the operation knob 11 and the knob is returned to the position of neutral N, the closing operation or the opening operation of the window is stopped. On the other hand, in the case of the auto operation, when the operation knob 11 is once rotated until the position of auto closing AC or auto opening AO, the closing operation or the opening operation of the window is thereafter continuously performed even when the hand is separated from the operation knob 11 and the knob is returned to the position of neutral N.
FIG. 3 is a view showing one example of the window opening and closing mechanism arranged in each window of the vehicle. Reference numerals 100, 101 and 102 respectively designate a window of an automobile, a window glass for opening and closing the window 100, and the window opening and closing mechanism. The window glass 101 is raised and lowered by operating the window opening and closing mechanism 102. The window 100 is closed by raising the window glass 101, and is opened by lowering the window glass 101. In the window opening and closing mechanism 102, reference numeral 103 designates a support member attached to the lower end of the window glass 101. Reference numerals 104 and 105 respectively designate a first arm and a second arm. One end of the first arm 104 is engaged with the support member 103, and the other end of the first arm 104 is rotatably supported by a bracket 106. One end of the second arm 105 is engaged with the support member 103, and the other end of the second arm 105 is engaged with a guide member 107. The first arm 104 and the second arm 105 are connected through a shaft in their intermediate portions. Reference numerals 3 and 4 respectively designate the above motor and the above rotary encoder. The rotary encoder 4 is connected to the rotating shaft of the motor 3, and outputs pulses of a number proportional to the rotating amount of the motor 3. The rotational speed of the motor 3 can be detected by counting the number of pulses outputted from the rotary encoder 4 within a predetermined time. The rotating amount of the motor 3 (the moving amount of the window glass 101) can be calculated from the output of the rotary encoder 4.
Reference numerals 109 and 110 respectively designate a pinion rotated and operated by the motor 3, and a gear of a fan shape engaged with the pinion 109 and rotated. The gear 110 is fixed to the first arm 104. The motor 3 can be rotated in the normal and reverse directions. The pinion 109 and the gear 110 are rotated by rotating the motor 3 in the normal and reverse directions so that the first arm 104 is rotated in the normal and reverse directions. In connection with this rotation, the other end of the second arm 105 is slid in the transversal direction along a groove of the guide member 107, and the support member 103 is moved in the vertical direction. Thus, the window glass 101 is raised and lowered and the window 100 is opened and closed.
When the operation knob 11 is located in the position of auto closing AC of FIG. 2 and the auto closing operation is performed, the above power window device has a function for detecting jamming of an object. Namely, as shown in FIG. 4, when the object Z is jammed into a clearance of the window glass 101 during the closing of the window 100, this jamming is detected and the closing operation of the window 100 is stopped or switched to the opening operation. The window 100 is automatically closed during the auto closing operation. Therefore, when a hand, a neck, etc. are jammed in error, such a jamming detecting function is arranged from the necessity of inhibiting the closing operation and preventing that an injury is inflicted on a human being. In the detection of the jamming, the control section 9 reads the rotational speed of the motor 3 as the output of the pulse detecting circuit 5 at any time, and compares the present rotational speed and the previous rotational speed, and judges the existence of the jamming on the basis of this comparing result. When the jamming of the object Z is generated in the window 100, the load of the motor 3 is increased and the rotational speed is reduced so that the changing amount of the speed is increased. When this speed changing amount exceeds a predetermined threshold value, the control section 9 judges that the object Z is jammed. The threshold value is stored to the memory 6 in advance.
The change of the rotational speed of the motor 3 is also generated by a vibration at the closing time of the door as well as the jamming of a foreign substance. When the rotational speed is changed by such a vibration, a case in which it is judged in error as the jamming of the foreign substance and the window is opened, might be caused although no foreign substance is jammed. As this countermeasure, it is considered to highly set the threshold value for judging the jamming. However, when the threshold value is merely raised, the load (hereinafter called “jamming load”) at a detecting time point of the jamming is increased by the raising amount of the threshold value. Therefore, a problem exists in that safety is reduced when a hand, an arm, etc. are jammed.
Therefore, in Japanese Patent No. 3156553 (patent literature 1), a power window device is proposed as a solving countermeasure of this problem. In this power window device, the threshold value is raised for only a constant time from the detection of the closing of the door. Thus, at the closing operation time of the door, no speed changing amount exceeds the threshold value and the erroneous judgment is prevented even when the rotational speed of the motor is changed by a vibration. After the constant time has passed from the closing of the door, the threshold value is returned to the original threshold value so that the normal jamming detection is performed. In Japanese Patent No. 3237519 (patent literature 2), a similar technique is also disclosed. In a power window device described in Japanese Patent No. 3237520 (patent literature 3), a road surface state is judged on the basis of the change of a pulse period according to the speed of the motor. When it is judged that the vehicle is running a bad road, the threshold value is changed so as not to generate the erroneous judgment of the jamming due to a vibration during the bad road running.
Power voltage supplied from a battery arranged in the automobile is generally not constant, but is changed in accordance with the state of an engine. Namely, the power voltage at a stopping time of the engine is e.g., 12 V In contrast to this, the power voltage at an operating time of the engine is raised to e.g., 14.5 V The rotation number of the motor depends on the power voltage. As the power voltage is raised, the rotation number is increased. Accordingly, in the system for raising the threshold value for only a predetermined time from the closing of the door as in patent literatures 1 and 2, the rotating amount of the motor is increased when the power voltage is high. The moving amount of the window glass is increased while a predetermined time has passed. Therefore, a problem exists in that the jamming load is increased and the jammed foreign substance is easily damaged. No countermeasures with respect to this problem are described in patent literatures 1 to 3.